WARSAW, Feb 14 (Reuters) - Poland's KGHM, one of the world's biggest copper and silver producers, said on Tuesday it considered justified to write down 5.87 billion zloty last year from the value of its oversees assets, mostly of Chilean Sierra Gorda mine.
KGHM also said in consolidated terms the impairment was justified at 5.19 billion zloty or $1.24 billion calculated on the base of the exchange rate at the end of 2016.
Earlier this month KGHM's partners in the Sierra Gorda project - Sumitomo Metal Mining and Sumitomo Corp also booked impairment loss for the mine, 79.9 billion yen and 33.6 billion yen respectively.
KGHM gained control over Sierra Gorda in 2011 when it bought Canada's Quadra FNX, for C$2.87 billion in the largest ever foreign acquisition by a Polish company.
KGHM will publish last year's results on March 16. ($1 = 4.0767 zlotys) (Reporting by Marcin Goclowski; Editing by Anna Wlodarczak-Semczuk)